computer graphics in the 1950s

Tony Duell ard at
Sat Oct 18 14:59:23 CDT 2008

> On 17 Oct 2008 at 21:38, Tony Duell wrote:
> > Did anyone try using 3 monochrome CRTs and combining the outputs 
> > optically (e.g. by back projectuion)? That would get round the need for a 
> > shadowmask 
> As Fred mentioned, projection TVs (I still see them), but convergence 
> was a headache. The fewer optics, the better.  Better to use field-
> sequential with a color wheel (as in the old CBS color TV system) as 
> various computer-to-film systems did.
> If you've never seen one, the color on the old CBS system was quite 
> good--far better than the RCA shadowmask tubes of the time.

Of course the problem, for TV, was that the signal was not compatible 
with the monochrome system (in either direction). That was, I believe, a 
major reason for not using sequential colour systems.

Of course this doesn't apply for vector graphics displays, and thinking 
about it, at least one vector display system did use a rotating colour 
wheel on a spectacle-like frame in front of the useres eyes. Not only did 
this give colour, but also a 3D effect (the wheel could blank off each 
eye alternately so that you could have the 2 images of a stereo pair 
viewed by each eye). The machine I am thinking of is, of course, the 
Vectrex video game. The colour/3D spectacles are, alas, very hard to find.


More information about the cctech mailing list